Chapter 4

Cell Structure and Function

What are Cells?
Based on the cell theory, cells are the building blocks of every organism—they serve as the basic unit of structure and function. New cells are…
Cell Size
4.2: Cell Size
The size of cells can vary widely—for instance, the smallest bacteria are 0.1 micrometers (μm) in diameter—about a thousand times…
Eukaryotic Compartmentalization
4.3: Eukaryotic Compartmentalization
One of the distinguishing features of eukaryotic cells is that they contain membrane-bound organelles—such as the nucleus and…
Prokaryotic Cells
4.4: Prokaryotic Cells
Prokaryotes are small unicellular organisms in the domains Archaea and Bacteria. Bacteria include many common organisms such as Salmonella and E.…
The Nucleus
4.5: The Nucleus
The nucleus is a membrane-bound organelle that contains a eukaryotic organism’s genetic instructions in the form of chromosomal DNA. This is…
Ribosomes
4.6: Ribosomes
Ribosomes are tiny organelles where the genetic instructions from messenger RNA (mRNA) are translated into protein. Both prokaryotic and eukaryotic…
Microtubules
4.7: Microtubules
There are three types of cytoskeletal structures in eukaryotic cells—microfilaments, intermediate filaments, and microtubules. With a diameter…
Mitochondria
4.8: Mitochondria
Mitochondria and peroxisomes are organelles that are the primary sites of oxygen usage in eukaryotic cells. Mitochondria carry out cellular…
The Extracellular Matrix
4.9: The Extracellular Matrix
The extracellular matrix (ECM) is a network of molecules—including fibers and gel-like substances—that surrounds cells and tissues. It…
Tissues
4.10: Tissues
Cells with similar structures and functions are grouped together into tissues in the body. These tissues, in turn, are combined in organs to carry…
Light Microscopy
4.11: Light Microscopy
The light microscope is an instrument used by researchers in many different fields to magnify specimens to as much as a thousand times their original…
Biology: Studying Mitochondria in Drosophila Ovaries
4.12: Biology: Studying Mitochondria in Drosophila Ovaries
A thorough understanding of mitochondrial regulation requires an understanding of the structure-function relationship. In this article, genetic…
Chemistry: From Constructs to Crystals
4.13: Chemistry: From Constructs to Crystals
β-barrels perform important functions within the outer membranes of Gram-negative bacteria, mitochondria, and chloroplasts. However, obtaining…
Developmental Biology: Structure-function Studies in Mouse Embryonic Stem Cells
4.14: Developmental Biology: Structure-function Studies in Mouse Embryonic Stem Cells
Proteins often contain multiple domains that carry out different functions. However, studies that entirely eliminate them can not distinguish such…
Immunology: Isolation of Exosomes from the Plasma of HIV-1 Positive Individuals
4.15: Immunology: Isolation of Exosomes from the Plasma of HIV-1 Positive Individuals
Exosomes are extracellular vesicles that are involved in HIV pathogenesis. Studying their role in this disease requires separating them from HIV…